U.S. Space-Based Positioning, Navigation, and Timing (PNT) Policy and Modernization

U.S. Space-Based Positioning, Navigation, and Timing (PNT) Policy and Modernization China Executive Management Development Training (EMDT) MITRE, McLean, VA 25 July 2006 Michael Shaw Director U.S. National Space-based PNT Coordination Office

Overview • What is Space Based PNT and GPS • How GPS and Its Augmentations Work • GPS Performance • Next-Generation GPS • U.S. Policy • International Cooperation

What is Space Based PNT and GPS? • Space Based PNT is GPS plus its augmentations • GPS is a space-based radio-navigation system • Satellites broadcast precise and synchronized time signals and data to allow users to estimate their position, velocity, and time • Augmentations improve GPS performance

The Global Positioning System • Baseline 24 satellite constellation in medium earth orbit • Global coverage, 24 hours a day, all weather conditions • Satellites broadcast precise time and orbit information on L-band radio frequencies • Two types of signals: • Standard (free of direct user fees) • Precise (U.S. and Allied military) • Three segments: • Space • Ground control • User equipment

FAIRBANKS ENGLAND SOUTH KOREA GAITHERSBURG USNO WASH D.C. VANDENBERG, AFB BAHRAIN HAWAII ECUADOR TAHITI SOUTH AFRICA AUSTRALIA ARGENTINA NEW ZEALAND Ground Antenna (GA) Master Control Station (MCS) Monitor Station (MS) Alternate Master Control Station (AMCS) National Geospatial-Intelligence Agency (NGA) Tracking Station Backup Master Control Station (BUMCS) Operational Control Segment Facilities COLORADO SPRINGS CAPE CANAVERAL Master Control Station KWAJALEIN ASCENSION DIEGO GARCIA

Nationwide Differential GPS Wide Area Augmentation System Continuously Operating Reference Stations Local Area Augmentation System U.S. Augmentations

Differential GPS Networks Space-Based Augmentation Systems Global Differential GPS System International GNSS Service International Augmentations

Commercial GPS Applications Span A Wide Range of Economic Activities Satellite Operations Power Grid Management Personal Navigation Surveying & Mapping Trucking & Shipping Aviation Communications Network Synchronization Recreation Railroads Fishing & Boating Offshore Drilling

Example Applications • Cell phones (e.g. e 911 services) • Farming • Boating • Fishing • Tracking wildlife • Atmospheric/Space weather • Visually impaired • Computer security • Games • Navigation -- Aircraft, land vehicles, ships, & satellites) • Precise timing • Surveying • Map making • Science • Hiking • Driving • Flying

New Commercial Applications Are Developed Every Day • Open pit mining • Child safety • Automatic snowplow guidance • Spacecraft control • Power grid management • Wireless mobile applications

GPS is a Global Public Service • Free access to civilian signals • One-way broadcast, like FM radio • Public domain documentation • Anyone can develop user equipment • Worldwide utility providing consistent, predictable, dependable performance • Critical component of global information infrastructure • Owned and operated by the U.S. Government • Paid for by U.S. taxpayers • Guided at a national level as multi-use asset • Acquired and operated by Air Force on behalf of USG Available Now—Empowering the Future

GPS – How does it work? • GPS receiver uses signal from at least four satellites to “triangulate” its position in space • Receiver knows several pieces of information: • Location of satellites • Time satellite sent data • Time it received data • Velocity data travels to receiver • Using this information, the receiver calculates its distance from the satellite and ultimately its position on the Earth

Time & Orbit Position Time & Orbit Position Time & Orbit Position FIX FOM 1 N 42* 01” 46.12” W 091* 38’ 54.36” EL + 00862 ft 3 menu 1 ON 2 4 5 6 7 WPT 8 POS 9 NAV CLR MARK 0 OFF NUM LOCK ZEROIZE Rockwell How GPS Works Time & Orbit Position Receiver Calculates 3-Dimensional Location and Time

Location Determination3D example Intersection of two spheres is a circle

Location Determination3D example The receiver dismisses the point located in space, leaving only one possible position on the earth Intersection of three spheres is two points

5 sec. 4 sec. 6 sec. 5 sec. 7 sec. 6 sec. So Why Do We Need 4 Satellites? • With receiver’s “inaccurate” clock—need 4 • If receiver had built in atomic clock—need 3 • 4th satellite measurement allows receiver to solve for 4th unknown (correction factor)

Constellation Status 29 Operational Satellites (Baseline Constellation: 24) • 16 Block II/IIA satellites • 12 Block IIR satellites • Modernizing 8 remaining Block IIR satellites • 1 Block IIR-M satellite • Transmitting new second civil signal • Continuously assessing constellation health to determine launch need • Next launch: September 2006

Recent Launches Providing worldwide position, navigation & timing GPS IIR-13 06 Nov 04 GPS IIR-14(M) 25 Sep 05 1st Modernized GPS Satellite GPS IIR-12 23 Jun 04 GPS IIR-1120 Mar 04 50th GPS Satellite

Civil GPS Performance Standard U.S. commitments to civil GPS performance are documented in the GPS Standard Positioning Service Performance Standard (2001) In support of the service availability standard, 24 operational satellites must be available on orbit with 0.95 probability (averaged over any day). At least 21 satellites in the 24 nominal plane/slot positions must be set healthy and transmitting a navigation signal with 0.98 probability (yearly averaged). System accuracy far exceeds current standard

. Improving GPS Performance with Augmentations Augmentations enhance GPS accuracy, monitor integrity • Sub-centimeter accuracy for geodesy, geology, etc. • 2-5 cm accuracy for real-time positioning, surveying, etc. • <3 m vertical accuracy with 6 second time to alarm for aviation

Perf ormance Representative Standard Performance Best Site Accuracy Horizontal 95% 2.5 m .677 m Vertical 95% 2.5 m .914 m Worst Site Accuracy Horizontal 95% 2.5 m 1.078 m Vertical 95% 2.5 m 1.574 m GPS Performance with WAAS U.S. Federal Aviation Administration developed the Wide Area Augmentation System (WAAS) to provide necessary accuracy, integrity, and availability to support flight operations during all phases of flight Based on observations from January to March 2006. Results are valid when the Localizer Approach with Vertical Guidance (LPV) service is available. During this time frame, LPV was available 98% to 99% of the time. Augmented GPS fulfills rigorous user needs today

Overview • What is Space Based PNT and GPS • How GPS and Its Augmentations Work • GPS Performance • GPS Modernization • U.S. Policy • International Cooperation

Benefits of GPS Modernization • For all users • System-wide improvements in accuracy, availability, integrity, and reliability • Backward compatibility • For civil users • Higher standalone accuracy • Robustness against interference • Improved indoor, mobile, and urban use • Interoperability with other GNSS constellations • For military • Enhances navigation warfare • Maintains international competitiveness

GPS Modernization Program Increasing System Capabilities w Increasing Defense / Civil Benefit Block IIA/IIR Block IIR-M, IIF Block III • Basic GPS • Standard Service • Single frequency (L1) • Coarse acquisition (C/A) code navigation • Precise Service • Y-Code (L1Y & L2Y) • Y-Code navigation • IIR-M: IIA/IIR capabilities plus • 2nd civil signal (L2C) • M-Code (L1M & L2M) • IIF: IIR-M capability plus • 3rd civil signal (L5) • Anti-jam flex power • Backward compatibility • 4th civil signal (L1C) • Increased accuracy • Increased anti-jam power • Assured availability • Navigation surety • Controlled integrity • Increased security • System survivability

Second Civil Signal • Designed to meet commercial needs • Freely available since Dec 2005 • Currently on 1 satellite • Will be on all future satellites • Expected to generate over $5 billion in user productivity benefits Benefits existing professional receivers Supports miniaturization, possible indoor use Increases accuracyfor consumers

Third Civil Signal • Designed to meet demanding requirements for transport safety • May also enable global, centimeter-level accuracy using new techniques • Opportunity for international interoperability

Fourth Civil Signal • Designed with international partners for interoperability • Modernized civil signal at L1 frequency • Original signal retained for backward compatibility • More robust navigation across a broad range of user applications • Improved performance in challenged tracking environments Under trees Inside cities

GPS III • Next-generation satellites are needed to accommodate increasing capabilities • Civil benefits • Provides operational capability for L2C and L5 • In combination with GPS IIR-M and IIF satellites • Delivers L1C for interoperability with Galileo, QZSS • Significant increase in system accuracy • Improved availability of accuracy with integrity • Revised acquisition strategy • Spiral development approach to reduce risk, increase flexibility • Separate contracts for space and ground segments to ensure best technology and most efficient implementation

GPS III Proposed Accuracy • Draft System Specifications • Includes the effects of receivers • Threshold = low-cost/low-performance receiver • Objective = high-cost/high-performance receiver

U.S. Policy History • 1983: President Reagan offers free civilian access to GPS • 1996: GPS declared a dual-use system under joint civil/military management • 1997: Congress passes law requiring civil GPS to be provided free of direct user fees • 2004: President Bush issues new U.S. policy on space-based PNT

Policy Objectives • Provide space-based civil PNT services free of direct user fees on a continuous, worldwide basis • Open, free access to information needed to use civil GPS and its augmentations • Improve performance of GPS and its augmentations - improving global services • Ensure civil services exceed, or are at least equivalent to, those of other international civil space-based PNT services • Improve resistance to interference for civil, commercial, homeland security, and scientific users • Seek to ensure that international PNT systems are interoperable with GPS and its augmentations • Or, at a minimum, are compatible

Organizational Structure WHITE HOUSE Defense Transportation NATIONALSPACE-BASED PNT EXECUTIVE COMMITTEE Co-Chairs: Defense, Transportation State ADVISORYBOARD Sponsor: NASA Commerce Homeland Security NASA COORDINATIONOFFICE Host: Commerce Joint Chiefs of Staff

Global Navigation Satellite Services (GNSS) Expanding • Sep 2005 – 2nd civil GPS signal • Dec 2005 –first Galileo test satellite • Dec 2005 –3 GLONASS satellites • This year – European EGNOS operational • Japan preparing for MSAS ops in 2007 and QZSS • India moving forward with GAGAN and IRNS • China Beidou, Compass Interoperability key to seamless global operations

Provide civil GPS and augmentation services free of direct user fees on a continuous, worldwide basis Provide open, free access to information needed to develop equipment Improve performance of civil GPS and augmentations to meet or exceed that of international systems Encourage international development of PNT systems based on GPS Seek to ensure international systems are interoperable with civil GPS and augmentations Or at a minimum, are compatible Address mutual security concerns with international providers to prevent hostile use U.S. Cooperation Strategy Outlined in 2004 Presidential policy on space-based positioning, navigation, and timing (PNT)

U.S. GPS Cooperation • Ongoing cooperation with Europe, Japan, Russia • Compatibility and interoperability • National security • Level playing field in global markets • Seeking formal relations with Australia, India, Brazil • Multilateral cooperation • U.N. International Committee on GNSS • ICAO, IMO, NATO

Europe • In 2004, United States and European Community signed historic agreement on GPS-Galileo cooperation • Recognizes importance of compatibility/interoperability for all parties • Agreed to spectrally separate signals for military, civilian, and public regulated services • Agreed to implement a common, open, civil signal on both Galileo and GPS III, free of direct user fees • Working groups establishedto continue dialogue: • Compatibility & Interoperability • Trade & Commercial Applications • Next-Generation GNSS • Security Issues June 26, 2004, press conference at U.S.-EU Summit in Ireland (U.S. Sec. of State Colin Powell, Irish Foreign Minister Brian Cowen, EU Vice-President Loyola De Palacio)

Japan • World’s largest consumer of GPS technology • U.S.-Japan cooperation began in 1998 • Initially focused on interoperability with MSAS, Japan’s GEO-based augmentation system • Promotes common principles such as free market access • Annual plenary meetings, technical working groups • Current focus is on Quasi-Zenith Satellite System (QZSS) • Regional system to complement, augment GPS over Japan • Will improve performance in urban canyons and mountains • Will freely broadcast GPS L1C, L2C, L5 signals • GPS-QZSS interoperability achieved MT-SAT used for MSAS

Russia • Cooperation started in 2004 • Working groups are pursuing GPS-GLONASS interoperability • Enhanced PNT through combined service • Combined search and rescue capabilities • Currently pursuing formal cooperation agreement GLONASS satellite

Multilateral group chartered through United Nations First meeting: December 2005 Purpose: Promote use of GNSS to improve efficiency and security of transport, search & rescue, geodesy, etc., particularly in developing countries Coordination among providers to improve compatibility and interoperability Assistance to developing countries in integration of PNT services Focal point for international information exchange Forum for addressing future user needs International Committee on GNSS

Summary • U.S. policy encourages and promotes worldwide use of civil GPS and augmentations • GPS performance is better than ever and will continue to improve • Augmentations enable high performance today • New GPS signal now available • Many additional upgrades in the future • International cooperation is a priority • Compatibility and interoperability are critical • Opportunity for partnership with all nations

Contact Information Michael E. Shaw, Director National Space-Based PNT Coordination Office Herbert C. Hoover Building, Room 6822 1401 Constitution Avenue, NW Washington, D.C. 20230 USA Ph: (202) 482-5809 Fax: (202) 482-4429 Michael.Shaw@PNT.gov Presentation and other GPS information available: www.pnt.gov

U.S. Space-Based Positioning, Navigation, and Timing (PNT) Policy and Modernization